In 1831, french explorer jules dumont d’urville proposed dividing the pacific island region into three groups based on geography and culture. the island groups were

Melanesia, Micronesia, and Polynesia

Explanation:

Melanesia is a group of bigger islands located just NorthEast of Australia, that goes from New Guinea to Fiji.

Micronesia is a series of smaller islands located NorthEast of New Guinea that extend up to Wake and Kiribati.

Polynesia is a large collection of about 10,000 small islands forming roughly a triangle between New Zealand, Hawaii and Easter Island.